8-hydroxyquinoline metal chelates



United States Patent 3,300,498 S-HYDROXYQUHNOLINE METAL CHELATES HermanGershon, North Bergen, and Walter J. Nickerson, Princeton, N.J.,assignors, by mesne assignments, to

Herman Gershon, Yonkers, N.Y. No Drawing. Filed May 8, 1962, Ser. No.193,296 8 Claims. (Cl. 260-270) This invention relates to new metalchelate compositions possessing pronounced antimicrobial properties.

The control of microorganisms is of vast importance. Among theindustrial areas where infestations of microorganisms require controlcan be mentioned the pulp, paper and textile industries where organismssuch as Leuconosloc mesenteroides, Penicillium spp., Asp'el'gillusniger, Trichoderma viride, and Myrothecium verrucaria are encountered.Certain of these organisms digest cellulose readily, and, unlesscontrolled, large economic losses result. For example, during prolongedstorage of textiles in warehouses, or in tropical areas, or duringtransportation while in the holds of ships where relatively highhumidity exists, fungal attack is a major problem. Particularlyimportant are protective agents which afiord prolonged control of thefungal infection and are easily removed when desired.

It is among the objects of the present invention to provide a class orgroup of novel chemical compositions useful in the control ofmicroorganisms.

Another object of this invention is to provide such chemicalcompositions which are effective in controlling microorganisms infestingcellulosic materials and can readily be removed therefrom when desired.

Still another object of this invention is to provide novel chemicalcompositions having powerful antifungal properties against organismsincluding Aspergillus niger, Trichode/ma viride, Myrothecium verrucaria,Penicillium sp. and T richophyton mentagrophytes, and also antibacterialactivity against Escherichia coli, Streptococcus faecalis,Staphylococcus aureus and Leuconostoc mesentcroides.

Other objects and advantages of the present invention will be apparentfrom the following detailed description thereof.

Compositions of this invention have the formula:

aryl in which M represents bivalent Cu, Cd, C0, Pb, Mn, Hg,

in which R=H, Cl, I R =H, Cl, I

3,300,498 Patented Jan. 24, 1967 ice R =H, Cl, I R =H, Cl, Br R4:,H, BIPreferred compositions of this invention are:

in which R, R and R have the values above given and M is Cu;

O O I in which R and M have the values above given and R =H, Cl;

in which R and M have the values above given;

in which R, R R and M have the values above given.

These metal chelates can be prepared, for example, by reacting asaturated or near saturated solution of an S-hydroxyquinolinium salt ina solvent, such as a lower aliphatic alcohol, e.g., methanol or ethanol,acetone, dioxane, chloroform, dimethylformamide or water, in whichsolvent the salt is sufficiently soluble to produce the saturated ornear saturated solution with a solution of the metal salt in an aqueoussolvent. Preferred metal salt solutions are the metal acetates,sulfates, chlorides and hydroxides. Stoichiometric or approximatelymolar amounts of the quinolinium salt and the metal salt are used. Thereaction temperature can be from room temperature, about 20 C., up tothe boiling point of the solvent used, under the pressure conditions atwhich the reaction is carried out. Temperatures near the boiling pointare preferably employed because the reaction proceeds faster at suchelevated temperatures. Desirably the reaction is carried out underatmospheric pressure conditions although it can be carried out underhigher pressures. The reaction mixture is agitated and the reaction iscontinued, while agitating, until the metal chelate precipitates and areaction mixture of uniform composition results, i.e., the metal chelateprecipitate is distributed substantially uniformly throughout thereaction mixture under the agitation conditions employed. The mixingwith agitation requires from a few minutes to prolonged periods as longas 24 hours or longer depending chiefly upon the reactants and thereaction temperature. t

The 8-hydroxyquinolinium salts can be the salts disclosed and claimed inthe co-pending application of Herman Gershon, Serial No. 152,025, filedNovember 13, 1961, now abandoned. This co-pending application disclosesthat hydroxy naphthoic acid salts of S-hydroxyquinoline having theformula:

HO X

in which X is hydrogen, chlorine or iodine, react with hydroxy naphthoicacid having the formula:

HO X

OOOHN in which X is the elements above mentioned;

(2) The 8-hydroxyquinolinium salts of 1-hydroxy-2- naphthoic acid havingthe formula:

in which X and R" are the elements above mentioned;

naphthoic acid having the formula:

in which R, R and X are the elements above mentioned.

The precipitated chelate compound can be removed from the reactionmixture of aqueous metal salt solution and saturated or near saturatedsolution of S-hydroxyquinolinium salt hereinabove described byfiltration the thus separated chelate compound washed with waterfollowed by -a rinse with a water-miscible organic solvent, such as thelower alcohols, acetone, dimethylformamide or dioxane. Employing themetal acetate in producing the reaction mixture, the latter reaches a pHof from 5 to 6 at completion of the reaction, at which pH the metalchelate formed is stable. The metal salts of other acids such as thesulfates or chlorides or the metal hydroxides when employed requireadjustment of the pH of the reaction mixture to the range of 56 toeifect precipitation of the metal chelate. Such adjustment is readilyeffected by alkali, e.g., NaOH, when the pH must be increased, or acidsuch as an inorganic acid, desirably HCl, when the pH of the reactionmixture must be reduced.

The metal chelates of 8-hydroxyquinolinium salts of salicylic acid,S-chlorosalicylic acid, 3,5-dichlorosalicylic acid, S-iodosalicylic acidand 3,5-diiodosalicylic acid can be prepared in substantially the samemanner as hereinabove described for the preparation of theS-hydroxyquinolinium salts of hydroxy naphthoic acid and its enumeratedhalo derivatives. For example, a saturated or near saturated solution of8-hydroxyquinolinium salicylic acid or the halo substituted salicyclicacid in a solvent such as those mentioned can be reacted with a metalsalt, preferably the metal acetate, sulfate or chloride, or with themetal hydroxide employing approximately equi-molar amounts of thequinolinium and the metal compound. The reaction temperature can be fromroom temperature up to the boiling point of the solvent used, under thepressure conditions at which the reaction is carried out. Temperaturesnear the boiling point .are preferably employed because the reactionproceeds faster at such elevated temperatures. Desirably the reaction iscarried out under atmospheric pressure conditions, although it can becarried out under higher pressures. The reaction mixture is agitated andthe reaction is continued while agitating until the metal chelate of the8- hydroxyquinolinium salt of salicylic acid or its derivativesprecipitates and a reaction mixture in which the metal chelateprecipitate is distributed substantially uniformly therethroughout underthe agitation conditions employed results.

Alternatively, the metal chelates, i.e., metal chelates of8-hydroxyquinolinium hydroxy naphthoic acid and its derivatives as wellas of 8-hydroxyquinolinium salts of salicylic acid and its derivatives,can be prepared by mixing the metal salt or metal hydroxide, thehydroxyquinoline derivative and the arylhydroxycarboxylic acid in waterwith or without a trace of wetting agent and adjusting the pH ashereinabove described to 56 during the course of the agitation. Themetal chelate which precipitates is separated by filtration orcentrifugal separation, washed with water followed by rinse with awater-miscible organic solvent.

The following examples are given to illustrate the invention, and itwill be understood that the invention is not limited to these examples.All percentages herein are given on a weight basis, temperatures indegrees centigrade.

5 EXAMPLE I 8-hydroxyquinolinium salicylate copper chelate To a solutionprepared from 48.0 grams (0.24 mol) of cupric acetate monohydrate in3120 ml. of 75% aqueous methyl alcohol was added a near boiling solutionof 67.2 grams (0.24 mol) of 8-hydroxyquinolinium salicylate in 125 ml.of methanol. The mixture was agitated for 30 minutes, filtered, washedwith water and followed by methyl alcohol. The yield of product wasnearly quantitative, melting point 266-267 and was suflieiently pure foranalysis. A sample recrystallized from chloroform melted at the sametemperature.

Analysis.--Calculated for C H NO Cu: C, 55.72; H, 3.19; N, 4.06; Cu,18.46. Found: C, 55.63; H, 3.30; N, 3.62; Cu, 18.79.

EXAMPLE II 8-hydroxyquin0linium 3-hydr0xy-2-naphthoate copper chelateMethod A.A mixture of 7.52 grams (0.04 mol) of 3-hydroxy-2-naphthoicacid, 5.8 grams (0.04 mol) of 8-hydroxyquinoline, 8.0 grams (0.04 mol)of copper acetatemonohydrate, 300 ml. of water and a trace of wettingagent was made and agitated overnight at room temperature. The productwas isolated by filtration, followed by water and methyl alcohol rinsesand drying for 4 hours at 80. The yield of chelate was nearlyquantitative and melted at 256258 and was sufliciently pure foranalysis. Samples of analytical purity were also prepared byrecrystallization from dimethyl formamide and from chloroform and meltedat 257259 and 259260, respectively.

Analysis.--Calculated for C H NO Cu: C, 60.82; H, 3.29; N, 3.55; Cu,16.12. Found: C, 60.99; H, 3.46; N, 3. 08;Cu, 16.10.

Method B.-To a solution of 25.0 grams (0.1 mol) of copper sulfatepentahydrate in 600 ml. of water was added 14.5 grams (0.1 mol) of8-hydroxyquinoline, and 18.8 grams (0.1 mol) of 3 -hydroxy-2-naphthoicacid. The mixture was agitated for about one hour and the pH was broughtto 89 with 22.4 grams of 50% caustic soda and adjusted to 5-6 withseveral drops of concentrated sulfuric acid. After agitating at roomtemperature for 8 hours, the product was isolated in quantitative yield.as previously described. Thematerial wasanalytically pure withoutfurther purification and melted at 259 260". i

. EXAMPLE III 8-hydr0xyquin0linium 4-chl0r0-1-hydroxy-2-naphth0atecopper chelate --This example differs from Example I chiefly in thatinstead of 8-hydroxyquinolinium salicylate, 8-hydroxyquinolinium4-chloro-1-hydroxy-2-naphthoate was used. The conditions otherwise werethe same.

A 92% yield of 8-hydroxyquinolinium 4-chloro-1-hydroxy-2-naphthoat-ecopper chelate was obtained having a melting point of 250 of suflicientpurity for analysis.

Analysis.Calculated for C H NO ClCu: C, 55.96; H, 2.82; N, 3.26; Cu,14.08. Found: C, 55.91; H, 2.79; N, 3.41; Cu, 14.20.

. EXAMPLE IV 8-hydroxyquinolinium 3,5-diid0salicylate copper chelate Toa solution of 10 grams (0.05 mol) of copper acetate monohydrate in 650ml. of 75% aqueous methyl,

6 Analysis.-Ca1culated for C H NO I Cu: C, 32.21; H, 1.52; N, 2.35; Cu,10.65. Found: C, 32.59; H, 1.36; N, 2.32; Cu, 10.25.

EXAMPLE V S-hydroxyquinolinium Z-hydroxy-I-naphth0ate copper chelateThis example differed from Example I chiefly in the substitution of8-hy-droxyquinolinium 2-hydroxy-1-naphthoate .for the quinolinium saltused in Example I. 8- hydroxyquinolinium 2-hydroxy-1-naphthoate copperchelate was obtained in a 64% yield having a melting point of 220-240.This compound showed fair solubility in methyl alcohol and this explainsthe lower yield of the compound. The product, isolated following theprocedure given in Example I, was sufficiently pure for analysis.

Analysis.Ca1culated for C H NO Cu: C, 60.83; H, 3.32; N, 3.55; Cu,16.09. Found: C, 60.32; H, 3.00; N, 3.28; Cu, 15.59.

EXAMPLE VI 8-hydr0xyquinolinium 3-hydroxy-Z-naphthoate lead chelate Asolution of 18.97 grams (0.05 mol) of lead acetate trihydrate in amixture of 300 ml. of methyl alcohol and 100 ml. of water was prepared.To this mixture was added a few drops of acetic acid and a solution of16.6 grams (0.05 mol) of 8-hydroxyquinolinium 3-hydroxy-2-naphthoate in250 ml. of methyl alcohol. The mixture was stirred for one-half hour,and the product was obtained in nearly quantitative yield in the usualmanner. It did not melt below 360. The product was sufliciently pure foranalysis.

Analysis.-Ca-lculated for C H NO Pb: C, 44.61; H, 2.43; N, 2.60; Pb,38.47. Found: C, 44.10; H, 2.32; N, 2.88; Pb, 38.93.

EXAMPLE VII 8-lzydr0xyquinolinium 3-hydr0xy-2-naphth0ate mercury chelateThis example diflered from Example VI chiefly in the substitution ofmercuric acetate for the lead acetate of Example VI. 8hydroxyquinolinium3-hydroxy-2-naphthoate mercury chelate was obtained in yield having amelting point above 360. The product was sufliciently pure for analysis.

Analysis.Calculated for C H NO Hg: C, 45.16; H, 2.46; N, 2.63. Found: C,44.71; H, 2.18; N, 2.66.

EXAMPLE VIII 7 5-c/2loro-8-hydr0xyquin0linium 3,5-dii0d0salicylazecopper chelate This example'differed from Example I chiefly in thesubstitution of 5-chloro-8-hydroxyquinolinium 3,5-diiodosalicylate forthe 8-hydroxyquinolinium salicylate. 5- chloro-8-hydroxyquinolinium3,5-diiodosalieylate copper chelate was obtained in 60% yield having amelting point of 303, of suflicient purity for analysis.

Analysis.Calculated for C H NO ClI Cu: N, 2.22; Cu, 10.17. Found: N,2.86; Cu, 10.79.

EXAMPLE IX 5-chl0r0-8-hydr0xyquinolinium 4,7-dibr0m0-3-hydroxy-Z-naphthoate copper chelate This example diflered from ExampleIV chiefly in the substitution of 5-chloro-8-hydroxyquinolinium4,7-dibromo-3-hydroxy-2-naphthoate for 8-hydroxy quinolinium3,5-diiodosalicylate. 5-chloro-8-hydroxyquinolinium4,7-dibromo-3-hydroxy-2-naphthoate copper chelate was obtained in 98%yield having a melting point of 259 of suflicient purity for analysis.

Analysis.-Calculated for C H NO Br ClCu: N, 2.39. Found: N, 2.48.

Twenty-four other chelate compounds were prepared following theprocedure of the above examples, which compounds are identified in thetables which follow, giving the antimicrobial screening data, in eachcase reacting the indicated 8-hydroxyquinolinium salt with the indicatedmetal salt, e.g., the acetate, employing the procedure hereinabovedescribed and exemplified by the above examples.

The colors of the chelate compounds are given in the following list.Particular colors may be desirable for certain applications.

Metal: Color of chelate compound Cu (II) Green. Cd (II) Off white. Co(II) Tan. Pb (II) Off white. Mn (II) Tan. Hg (II) Orange. Zn (II)Yellow. Fe (II) Steel gray. Fe (III) Blue black. Al (III) Yellow.

The novel metal chelates can be applied to the material to be protectedin solution form, or by precipitation as the result of successive dipsin solutions of the preformed salt (hydroxy carboxylic acid salts of8-hydroxyquinolines) followed by a dip in a solution of the metal salt(e.g. acetate). Solutions of the metal chelate compounds having aconcentration of about 0.1% to saturation in such solvents aschloroform, dioxane or dimethylformamide can be used.

By the alternative method of precipitation of the chelate compound onthe material to be protected, such as cotton fabric, the fabric is firstimpregnated with the S-hydroxyquinolinium salt dissolved in a solventsuch as acetone. The impregnated fabric, from which the solvent isallowed to evaporate, is subsequently dipped into an aqueous solution ofthe desired metal salt (preferably the acetate) -of concentration 0.110%at temperatures ranging from ambient to near boiling. The pH of themetal salt solution is kept between and 6. The fabric is then rinsed inwater and allowed to dry.

The metal chelate compounds herein disclosed afford prolongedantimicrobial protection and can be removed, should that be desired, bytreatment of the fabric with dilute acid followed by successive rinseswith dilute alkali and water. The first acid rinse decomposes thechelate and keeps the metal and quinoline in solution, and the alkaliremoves any remaining hydroxy carboxylic acid and residual acid from thefirst acid rinse.

The following test demonstrates the effectiveness of the metal chelatecompounds in protecting cotton fabric against fungi. This antifungaltest is that prescribed by The American Society for Testing Materials,Committee D-l3, ASTM Standard on Test Materials, 77, Philadelphia, 1943.Six inch by one inch strips of white cotton cloth weighing 570580 mg.each were used. These strips were immersed in a 0.1% solution of8-hydroxyquinolinium 3-hydroxy-2-naphthoate copper chelate indimethylformamide, and the solvent was allowed to evaporate. Each stripcontained from 0.5 mg. to 0.6 mg. of the protective agent, i.e., about0.1%.

French square bottles (i.e., bottles square shaped in cross-section) of16 ounce capacity were used as the incubation chambers. Into each bottlewas placed a standard liquid inorganic nutrient medium for fungi havingthe following inorganic salt composition:

Inorganic salts: Grams/liter K HPO 1.3940 MgSO 0.7395 NH NO 1.0006 NaCl0.005 Fe, Zn, and Mn as $0.; 0.001

Into each bottle while on its side was placed a glass filter sheet toact as a support for the cotton strip and to prevent its submersion inthe solution. Sufficient inorganic salt solution was introduced intoeach bottle to soak the glass filter sheet therein, and the cotton stripwas then placed on the filter sheet. The cotton-strip became soaked withinorganic medium by capillarity, and the bottles were each capped withPyrex glass wool and autoclaved for 20 minutes at 15 p.s.i.g.

To each sterile chamber thus produced was added 1 ml. of sporesuspension containing 6x10 spores/ml. Penicillium sp. and Myrotheciumverrucaria were used as the test organisms.

Controls for each organism consisted of one chamber containing no cottoncloth, one chamber containing unprotected cotton cloth, and one chamberwhich remained uninoculated. Three replicates of each bottle were used.

The bottles, prepared as above described, were incubated at 2830 C. for7-10 days. At the end of this period it was observed. The uninoculatedbottles and the bottles containing no cotton showed no fungal growth,the bottles with unprotected cotton showed good fungal growth, and thebottles containing cotton cloth protected wtih S-hydroxyquinolinium3-hydroxy-2-naphthoate copper chelate showed no fungal growth.

This test demonstrated the effectiveness of 8-hydroxyquinolinium3-hydroxy-2-naphthoate copper chelate in protecting cotton andparticularly cotton cloth against infestation by the fungi employed astest organisms.

Table I presents the antibacterial activity of 33 metal chelatecompounds as determined by the disc-plate method, and Table II containsthe corresponding antifungal results. The organisms employed in ourscreening system included five bacteria (Escherichia coli, Pseudomonasaeruginosa, Leuconcstoc mesenteroides, Staphylococcus aureus, andStreptococcus faecalis) and five fungi (Aspergillus nigcr, T richodcrmaviride, Myrozhecium verrucaria, Penicillium sp., and Trichophytonmentagrophytcs). For the antibacterial testing, the following media wereemployed: E. coli and Rs. aeruginosa, nutrient agar (Difco); S. aureus,nutrient agar (Difco) enriched with 10% of \beef serum; S. faecalis andL. mesenteroides, eugon agar (BBL). The fungal media employed were asfollows: A. niger, T. viriae, M. verrucaria, and Penicilliurn sp.,Sabourauds dextrose agar (Difco) and T. mentagrophytcs, Sabouraudsdextrose agar enriched with 10% of beef serum.

The antibacterial tests were conducted in the following manner: to ml.of agar medium at 45 was added 1 ml. of inoculum (18 hour culture of therespective organism grown on eugon broth (BBL) at 37). While stillliquid, the inoculated agar culture medium was distributed into 10 cm.Petri dishes at the rate of 15 ml. per dish. Six mm. filter paper discs,impregnated with three levels of com-pound each, 10 10 and 10micrograms/ disc were placed on the hardened agar and incubated at 37for 18 hours. The lowest level of compound causing inhibition wasrecorded.

For the antifungal studies, a spore suspension of the respectiveorganism was prepared in 10 ml. of sterile 0.9% NaCl solution from aseven day culture of each fungus on a test tube slant of Sabouraudsdextrose agar at 2830. The 10 ml. of spore suspension was thenincorporated into 500ml. of medium at 45 and 15 ml. portions ofinoculated medium were poured into 10 cm. Petri dishes and allowed toharden. Filter paper discs, 12 mm. in diameter, which had previouslybeen impregnated with three levels of compound, 10*, 10 and 10micrograms/disc, were placed on the hardened agar and al-- lowed toincubate at 2830 for five days. The lowest level of compound causinginhibition was recorded.

In Table I which follows, E. .c. is Escherichia coli; P.a. isPseudomonas aeruginosa; S. a. is Staphylococcus aureus; S. f. isStreptococcus jaecalis and L. m. is Leuconostoc mcsentcroides:

It Will be noted that the present invention provides a class of novelchemical compositions useful in the control of microorganisms,particularly, but not confined to those infesting cellulosic materials,such, for example, as cotton fabrics, paper and pulp. The metal chelatesof this invention when applied give prolonged control overmicroorganisms and can readily be removed when desired by successivetreatments with dilute acid, alkali and water.

It will be understood that this invention is not to be limited to thedisclosure herein except as indicated by the appended claims.

What is claimed is:

1. A metal chelate having the formula:

are positioned on adjacent carbon atoms of the aryl nucleus M isselected from the group consisting of bivalent copper, cadmium, cobalt,lead, manganese, mercury, zinc, and iron; aryl is selected from thegroup consisting of in which R is selected from the group consisting ofhydrogen, chlorine and iodine; R is selected from the group consistingof hydrogen, chlorine and iodine; R is selected from the groupconsisting of hydrogen, chlorine and iodine; R is selected from thegroup consisting of hydrogen, chlorine and bromine; and R is-selectedfrom the group consi t ng of hydrogen and. bromine and the bonds 12 tothe aryl group are attached to adjacent carbon atoms in ortho positionin respect to each other.

2. 8-hydroxyquinolinium salicylate copper chelate. 3.8-hydroxyquinolinium 3-hydroxy-2-naphthoate cop- 5 per chelate.

4. 8-hydroxyquinolinium 2-hydroxy-1-naphthoate copper chelate.

5. 8-hydroxyquinolinium 3-hydroXy-2-napht-hoate lead chelate.

6. 8-hydroxyquinolinium 3-hydroXy-2-naphth0ate mercury chelate.

7. A metal chelate having the following formula:

OH CH 110 0 CH i II I E N l o\ F /CHGE HO/ \CH CH=OH 8. A metal chelatehaving the following formula:

in which M is a metal selected from the group consisting of bivalentcopper, cadmium, cobalt, lead, manganese,

mercury, zinc and iron.

References Cited by the Examiner UNITED STATES PATENTS 1,754,251 4/1930Yates 2158 2,474,818 7/ 1949 Burckhalter et al. 260286 2,608,556 8/1952Kalberg 260-270 2,618,645 11/1952 Bowles 260270 2,681,910 6/1954Burckhalter 260-286 2,799,615 6/ 1957 Heymons et al. 2,871,091 1/1959Passedovet 21-58 2,891,011 6/1959 Insal aco 25262. 1 FOREIGN PATENTS893,513 7/1944 France. I 7

OTHER REFERENCES Badger, The Chemistry of Heterocyclic Compounds, pp.31819, (1961).

ALEX MAZEL, Primary Examiner.

D. McCUTCHEN, NICHOLAS S. RIZZO, HENRY'R.

JILES, Examiners.

D. M. KERR, D. G. DAUS, Assistant Examiners.

1. A METAL CHELATE HAVING THE FORMULA: